Automotive vehicle



Mam}! 1949- w. F. ROCKWELL ETAL 2,462,902

- AUTOMOTIVE VEHICLE Original Filed March 23. 19 44 6 Sheets-Sheet 1 Wa /fer f. Rbckrve fiererr M (fee-5e March 1, 1949. w, ROCKWELL ETYAL 2,462,902

AUTOMOTIVE VEHICLE Original Filed March 25. 1944 v 6 Sheets-Sheet 2 In ze rm dim? Neutral March 1, 1949. w. F. ROCKWELL ETAL AUTOMOTIVE VEHICLE I Original Filed March 23. 1944 v 6 Sheets-Sheet 3 w. F. RCCKWELL ETAL March 1, 1949.

AUTOMOTIVE VEHICLE 6 Sheets-Sheet 5 Original Filed March 23, 1944 March 1, 1949.

W. F. ROCKWELL EFAL AUTOMOTIVE VEHICLE Original Filed March 23 1944 6 Sheets-Sheet 6 /4 /feese Patented Mar. 1, 1949 AUTOMOTIVE vanrcm Walter F. Rockwell, Detroit, Micln, and Beverly W. Keese, Oshkosh, Wis., assignors to The Timken-Detroit Axle Company, Detroit, Mich, a corporation of Ohio Original application March 23, 1944, Serial No.

527,782. Divided and this application September- 10,1945, Serial No. 615,384

, 13 Claims. 1

This invention relates to improvements in automotive vehicles and has particular reference to a heavy duty automotive vehicle having a main engine furnishing the power under most operating conditions and a booster or auxiliary engine for furnishing supplementary power at times when the power of the main engine is inadequate to maintain a desired vehicle speed. This is a division of Serial No. 527,782 filed March 23, 1944 now United States Letters Patent No. 2,384,782 issued September 11, 1945.

Various arrangements have been heretofore providing a plurality of motors for driving a vehicle having motors of like or different capacities operating through the same drive lines and designed either for alternative or simultaneous operation without regard to the tractive effort that can be absorbed by the driving Wheels. Such vehicles have in general not been practical because of the excessive tire and other wear and vehicle maintenance expense, inefficiency of operation, difilculty of control on the part of the driver, and other practical disadvantages. The only multiple motor road vehicles that have been heretofore successful to our knowledge are of the type in which separate wheels or axles are driven simultaneously by individual motors in normal operation.

The foregoing problems we have solved by providin main and booster. engines driving different wheels through independent drive lines, con-' trolled through a novel control arrangement and having maximum powers insuf ficient to slip the wheels driven thereby under normal road conditions. In the preferred embodiments of our invention, the booster engine is operative only physical effort in shifting when the transmiswhen the power of the main engine is insufiicient to maintain the desired vehicle or tractor and trailer speed under particular conditions. Our invention has been found in long comparative road tests to have material advantage in reduced running time, increased load carrying capacity, improved fuel consumption and noninterference with other trafiic on the highways.

In the earlier embodiments of our invention disclosed in said co-pending applications, while providing various important advantages over the prior arrangements, it has been found that the control arrangements used have imposed additional burdens on the drivers of the vehicle which have been accentuated by the increased loads carried and increased speeds permitted. For example, with manual operation required to start the prior booster of auxiliary engines of the prior disclosures, the driver has had to disions of the two engines were coupled together by previous mechanical devices, and has experienced difllculty in controlling the increased load on steep grades or at high speeds with previous conventional brake equipment.

It is therefore among the objects of the present invention to provide a heavy duty booster engine vehicle with improved controls and brake equipment effective to relieve the driver of most or all of the excess burden over operating a conventional single engine vehicle of the same general class and to so proportion the loads on the vehicle parts and tires that undue wear and strain will not occur.

A further object resides in the provision of servo controls for the clutching and shifting operations of the booster engine which operate smoothly and substantially automatically and with which substantially no additional skill, attention or physical efiort on'the part of the driver is required when both engines are operating than when only the main engine is in operation.

A further object of the invention is to provide in a dual engine vehicle wherein separate engines are provided for driving different drive axles, a fluid pressure controlled interlock between the transmission shifting mechanisms of the respective drives for operating them in desired relation.

It is a further object of the invention to provide a novel fluid pressure controlled interlock between the clutch mechanisms in the respective drives between individual engines and associated drive axles in a dual engine vehicle.

A further object of the invention is to provide a novel dual engine vehicle drive arrangement wherein different engines drive separate drive axles and operability of the clutch mechanism between one of said engines and its axle is dependent on the condition of operation of said one engine.

A further object of the invention is to provide novel valve arrangements controlled by transmission shifting movements at one engine drive for controlling fluid pressure actuated transmission shift devices at the other engine drive in a dual engine drive vehicle.

grades without any material increase in physi cal effort and without damage to the brake equipment.

Other objects and advantages will be more particularly pointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawings, in which like reference numerals are used to designate similar parts throughout, there is illustrated a suitable mechanical embodiment for the purpose of disclosing the invention. 'The drawings, however, are for the purpose of illustration only and are not 'to be taken as limiting or restricting the invention since it will be apparent to those skilled in the art that various changes in the illustrative construction may be resorted to Without in any way exceeding the scope of the invention.

In the drawings:

Figure 1 is a side elevational view of the chassis of a vehicle constructed according to the invention, a portion being broken away to further illustrate the construction thereof;

Figure 2 is a top plan view of the vehicle chassis illustrated in Figure 1;

Fig. 2A is a diagrammatic representation of the clutch control arrangement of Figures 1 and 2; v

Figure 3 is a side elevational view on an enlarged scale of the auxiliary engine transmission shown in Figures 1 and 2;

Figure 4 is an end elevational view of the auxiliary engine transmission shown in Figure 3;

controlled by the shift device of the main engine transmission;

Figure '7 is a vertical sectional view of a portion of the valve taken along the line of Figure 5;

Figure 8 is a sectional view' similar to Figure '7 showing a different operative position of the valve;

Figure 9 is a sectional view of the valve shown in Figure 6 taken along the line 99 of Figure 5;

Figure 10 is a sectional view similar to Figure 9 showing a different operative position of the valve from that illustrated in Figure 9;

Figure 11 is a vertical sectional view similar to Figure 9 showing a different operative position of the valve from those illustrated in Figures 9 and 10;

Figure 12 is a plan view of mechanism for rendering the auxiliary engine clutchoperative by the main clutch pedal when the auxiliary engine is operating;

Figure 13 is a sectional'view on the line I3-l3 of Figure 12;

I Figure 14 is a diagrammatic sectional view of an improved brake arrangement; and

Figure 15 is a diagrammatic view of a suitable starting and ignition circuit for the auxiliary en.- gine.

Referring to the drawings in detail and particularly to Figures 1 and 2, the numeral 20 generally indicates a vehicle frame supported from front and rear road engaging wheels, as indicated at 22 and 24, by conventional springs, or other suspending means, not illustrated.

Frame 20 carries a main engine 25, connected through a clutch 28, change speed transmission 30, propeller shaft 32, two speed rear axle drive gear 34, difierential 36 and rear axle 38 with the rear wheels 24, and also carries a 'Patent vNo. 2,183,667 issued December 19, 1939,

to Lawrence R. Buckendale, and may be shifted by a servo device 32' actuated in one direction by a compression sprin not illustrated, and in the opposite direction by the pressure differential existing between the main engine intake manifold and atmospheric pressure. The connection 49 between the main engine intake manifold and the servo device 32' may lead through a suitable manually actuatable pneumatic valve 53, shown in more detail in co-pending application Serial No. 506,582, filed October 16, 1943, now United States Letters Patent No. 2,384,781 issued September 11, 1945, which valve may constitute a portion of the automatic apparatus which controls the starting and stopping of the booster engine. As illustrated, the valve is interposed in the fluid connection 49 between the main engine intake manifold and the rear axle clutch actuator 32 sothat it functions to select the rear axle drive gear ratio. This valve is provided with a shaft extension 51 carrying aradial arm 59 connected with a switch 214 which is incorporated in the auxiliary engine starting circuit in a manner illustrated in Figure 15 and which functions to control the starting of the auxiliary" engine in a manner hereinafter described.

Although the main engine and booster engine driving connections have common controls, as will later appear, they are drivingly independent of each other and the power output capacity of each engine is based on the traction capacity of the axle to which'it is connected. Thus, when the main engine is connected to a dual wheel rear axle, and the booster engine is drivingly connectable to a single wheel front axle carrying approximately one half the load carried by the rear axle, the booster engine might conveniently have a power output capacity approximately one halfthat of the main engine. The invention is not limited however to any specific ratio of the power output capacities of the two engines,.it being important only that the capacities of the engines shall correspond to the avail-' -vice as indicated at 54 and suitable ignition apparatus, including coil 55, controlled by a suitable electric circuit indicated at 55 in Figure aceaooa tor vehicle, and the drive gear 48 may be engaged by a servo device 62 having a spring which acts to disengage the gear and a connection 64 with the intake. manifold of the booster engine, whereby the pressure differential between the booster engine manifold pressure and the atmospheric pressure will overcome this springwhen the booster engine is operating and engage the gears thereby completing the drive between the booster engine propeller shaft 46 and the front driving axle 52. 8

Auxiliary engine transmission shift The booster engine transmission 44 is shifted by a set of pneumatic servo devices 66, 68 and 18, particularly illustrated in Figures 3 and 4, under the control of the valve I2 particularly illustrated in Figures 5-11, inclusive. Valve I2 controls application of the auxiliary engine intake vacuum to fluid pressure actuated transmission shift devices for the change speed transmission as.

The three servo units 66, 68 and I8 are similar in construction, which construction'is particularly illustrated in connection with the unit ID.

This unit comprises a two part metal casing l8 enclosing a transverse diaphragm l6 and a coiled compression spring I8. The diaphragm is connected at its center to an operating shaft 92 which extends through an apertured bushing 88, and a fluid connection I02 leads to the interior of the casing at the end thereof opposite the bushing 88. With this arrangement the compression spring urges the diaphragm and operating rod in one direction and these are moved-in the opposite direction when the interior of the casing is subjected on the side connected with the fluid conduit to a fluid pressure less than atmospheric. Openings I8 are provided in the casing on the atmospheric pressure side of the diaphragm.

The servo unit 66, through its operating rod 82,

to the unit 68 is effective to move lever 84 from direct drive to neutral when further movement is limited by the bottom of the slot in rod 82 and also to move lever 84 from its neutral to its intermediate speed position when the stop constituted by the upper position of rod 82 is removed.

Unit 18 moves the rod 92 and slot 88 downwardly toremove the stop at neutral for the lever 84 so that the intermediate speed may be engaged by the application of vacuum to unit 68.

The manifold vacuum is applied to the unit 68 through the conduit I86 and to the unit I6 through the conduit I 82.

Application of atmospheric and manifold pressure to the diaphragms of the servo units is controlled by the valve, generally indicated at I2 and particularly illustrated in Figures 5-11, inclusive. This valve comprises casing I04 adapted to be mounted on the vehicle adjacent to the. main engine transmission shift lever, a fragment of which is shown in Figure 9 and indicated by the numeral I06. The casing has a pair of parallel bores I08 and III] within which are slidably mounted respective valve plungers H8 and H 3. These plungers project atone end outside of the casing and 'carry on their projecting ends respective gates or lugs 'I I6 and H8 engageable by finger I20 formed on the end of bracket arm I23 welded or otherwise firmly secured on gear shift lever I86.

When the main transmission is in neutral, plunger IN will occupy the position in bore Iiil illustrated in Figure '7 in which position port I28, connected with the atmosphere through the filter I28, is connected through annular reduction I28 on the valve stem and port I 38 with conduit 88 leading to servo unit 66, thus permitting the spring in unit 66 to maintain the auxiliary transmission low speed gear train in neutral. Plunger 40 I i2, at the same time, occupies the position in bore the lever arm 84 and shaft 86, controls the low gear ratio of the auxiliary engine transmission, the spring urging the mechanism to a neutral position and the application of vacuum through the conduit 88 moving the diaphragm against the spring to engage the low speed gear. The intermediate and high speed gear ratios are controlled by the units 68 and I0 through their operating shafts 86 and 82, the lever arm 94 and the shaft 86.

In this arrangement when there is no application of manifold vacuum to either of these units 68 and 10 the spring in unit 68 forces the lever 34 to the position shown in full linesin Figure 3 in which the transmission is in its high speed gear ratio. It manifold vacuum is applied to the unit 68 only, the lever 94 will be turned to the indicated neutral position in which both inter- I08 illustrated in Figure 9, in which position conduit I80 leading to servo unit 68 is connected with the atmosphere through filter I 26, port I32, annular groove I34 on valve stem I I2 and port I36 thus permitting the spring in unit 68 to urge lever 94 in an anti-clockwise direction, as viewed in Figure 3, toward the third or direct speed drive of the auxiliary transmission. At the same time,

however, conduit I 82 leading to servo unit I6 is connected through hole I88, elongated port I46 in valve stem II2, axial bore I42 in the valve stem, the end of bore I08, branch channel I44 leading into the end of bore I08, hole I46 and conduit I48 with the interior of the intake manifold' of the booster engine.

If the booster engine is operating, the pressure differential exerted on diaphragm 16 will pull the diaphragm downwardly, as viewedin Figure 3, until the end of rod 92 within the unit strikes abutment I58 stopping rod 82 in a position in which the upper end of slot 98 holds lever, 94 in its neutral position in which neither the high nor intermediate speed ratios of the auxiliary transmission can be engaged. If there is no vacuum in the booster engine intake manifold, spring I8 will move shaft 82 upwardly permitting lever 84 to swing until the direct speed drive of the auxiliary transmission is engaged, which is the normal condition of this transmission when the booster engine isnot operating. At the same time the booster engine will be disengaged from its associated driving axle by servo unit 62, as

described above.

When the main transmission is moved to the low or creeper speed position, plunger III does 7 r not move out of its neutral position but plunger II4 is moved outwardly with respect to bore II8. Annular groove I28 however is of suflicient length to keep conduit 88 connected with the atmos-' phere so that the low auxiliary transmission speed remains in neutral and, if the booster engine is operating, the high and intermediate speed gear,

trains also remain in neutral, so that the booster engine is not drlvingly connected with its associated axle when the main transmission is in low or creeper gear ratio.

When the main transmission isshifted to second speed plunger II2 remains in the neutral position with the effect described above, but

plunger I I4 is moved inwardly relative to bore I I to the position particularly illustrated in Figure 8 in which conduit 88 is connected through port I30, hole I52, axial bore I54 in plunger 4, branch channel I44, hole I46 and conduit I48 with the booster engine intake manifold, port I24 leadingto the atmosphere through filter I26 being cut off. Now, if the booster engine is operating,

' the application of the manifold vacuum to unit I I66 with one or the other of notches I58 and I60 provided in plunger I I4.

If now the main engine transmission is shifted from its second to its third speed gear ratio, passing of shift lever I06 through neutral will cause finger I to return plunger II4 to its neutral position and engage in lug I I6 of plunger I I2 and movement of the lever to place the main transmission in the third speed gear ratio will move plunger II2 to the position particularly illustrated in Figure 10.

In the position particularly illustrated in Figure 0 conduit I00 is connected with the booster engine intake manifold through hole I36, port I6.I and bore I42 while, at the same time, conduit iliary transmission gear drives in neutral when the booster engine is operating, as explained above.

Plunger II2 thus has three positions in which it is steadied by spring pressed detent I66 enga ing in one or the other of notches I68, I10 and I12.

Auxiliary engine clutch control mechanism The main engine clutch 28 may be operated by a suitable foot pedal, not illustrated, in the conventional manner. In order to obtain operation the adjacent end of torque shaft I80 and is 00-- axial therewith. A bracket member I86 is clamped upon the end of shaft I84 and rotatably receives the end of shaft I80 and is provided with a bore I88 extending transversely of shaft I88 within which is a slidable plunger or drop pin I80. Pin I80 is provided with an annular groove I82 intermediate its length, and shaft I80 is provided with a notch I84, the groove and notch being so arranged that, when the groove of the plunger is centered over the shaft I80, the shaft may rotate freely in bracket I86 but, when the plunger is moved to bring a portion thereof beyond the annular groove in line with shaft I80, the shaft will be locked relative to bracket I88 and rotational movements of shaft I80 will be transmitted to shaft I84 so that operation of the main engine clutch will simultaneously operate the auxiliary engine clutch. This arrangement constitutes a simple, automatically actuated drop I pin construction for operatively connecting the two clutches together when the booster engine is operating.

Plunger I 80 is connected at one end to the center of diaphragm I84 peripherally clamped in a housing I86 the interior of which is connected I02 will be connected with the booster engine intake manifold through hole I38, elongated port I40 and bore I42 through branch channel I44, hole I46 and conduit I48. With this position of valve plunger I I2, manifold vacuum will be applied to both units 68 and I0 moving rod 80 upwardly and rod 82 downwardly, as viewed in Figure 3, and swinging lever 84 to the indicated intermediate speed position.

When the gear shift lever is moved to place the main transmission in its high or direct speed drive, plunger II2 will be moved to the position illustrated in Figure 11. In this position of the plunger conduit I00 is connected with the atmosphere through hole I36, annular groove I34, hole I32 and filter I28. At the same time, conduit I02 will be connected with the atmosphere through hole I38, annular groove I62, hole I64 and filter I26 thus connecting both of the units 68 and I0 with the atmosphere and permitting the compression springs therein to respectively move rod 80 downwardly and rod 82 upwardly, thereby tilting lever 84 to the indicated direct drive position for the auxiliary transmission.

Return of the gear shift lever to neutral will place the plungers in the locations shown in Figures '7 and 9 respectively and place all of the auxthrough conduit I98 with the booster engine intake manifold. Normally plunger I is held in position to release the shaft I80 by coiled compression spring 200, but, when the booster engine is operating, the effect of the intake manifold vacuum overcomes the force of spring 200 and moves plunger I80 into position to interlock shafts I80 and I84.

' Operation of the auxiliary engine transmission shifting mechanism and clutch control From the above description it will be apparent that when the booster engine is not operating, the auxiliary engine clutch will not be operated and the auxiliary engine transmission will remain in its direct speed drive gear ratio, while the booster engine propeller shaft will be drivingly disconnected from the associated driving axle. When the booster engine is operating, the booster clutch will be connected with the main engine clutch so that both clutches will be operated simultaneously and the servo shifting means for the booster engine transmission will be connected with the main engine transmission in such a manner that whenever the main engine transmission is in neutral or in its lowest speed drive gear the booster engine transmission will be in neutral, but, when the main engine transmission is placed in either its second, third or fourth speed drive, the booster engine transmission will be simultaneously placed in its corresponding low, intermediate or high speed drive and the booster engine propeller shaft will be drivingly connected driving axle.

Improved brake installation The arrangement shown in Figure 14 illustrates an improved brake which has been found desirable for certain installations, particularly where it is necessary to hold a heavy load on a steep grade. This brake is preferably added in addition to the conventional wheel brakes of the vehicle but, in some installations, might be sub stituted for the rearwheel brakes.

In this arrangement a brake drum 280 is mounted by a suitable spline connection 282 on the power shaft 284 which projects from the rear axle housing 34 and is connected with the main engine propeller shaft 32 through a suitable universal joint. An anchor plate 286 is rigidly mounted on the housing and carries a suitable external brake band or shoe 288 moved into engagement with the drum 280 by suitable conventional means, not illustrated.

With this arrangement the conventional gear reduction between the rear driving axle 38 and the shaft 284 through the ring and pinion bear and through the two speed drive gears can be used to advantage in reducing-the actual torque imwith the associated posed on the brake so that the frictional resistance of the brake is greatly multiplied as it is applied to the road wheels 24 thus permitting a magnified braking effort with a minimum of heat dissipated by the brake and with a brake mechanism of reasonable size and weight.

Improved starting and ignition circuits for the auxiliary engine A suitable starting and ignition circuit for the booster engine is diagrammatically illustrated in Figure 15. It is to be understood. however, that the invention is not limited to this particular circuit but either a fully automatic circuit or a manual circuit may be utilized if desired instead of'the combined manual and automatic circuit conveniently be the master ignition switch of the vehicle. This switch has two operational posithrough a switch, generally indicated This switch may be of the low voltage oil damped type'and comprises, in general. a casing 230 within one end of which is mounted aflxed contact member 232 insulated from the casing and connected with thesolenoid 205 by the conductor 234; and a movable contact 236 electrically connected with the casing bya compression spring 238, the casing being suitably ground by the ground connection 226. An oil pressure conduit 240 leads from the output side of the auxiliary engine lubricating oil pump to a chamber in the casing 230 in which the contacting ends of the members 232 and 238 are located, one end of this chamber being constituted by the end of the casing supporting the contact member 232 and the other end being constituted by a partition 242 providing a bearing for the movable contact member 236.. Aslight clearance is preferably provided between the member 238 and the bearing 242 so that a small quantity of oil can flow from the conduit 240 out of the chamber and through a different part of the casing to the oil return conduit 244 in order to replace cold oil in tions, as indicated by the arrows labelled "automatic" and manual. and has a third inoperative position, illustrated in full lines inFigure 15, in which the ignition circuits of both engines are interrupted. The main engine ignition circuit including the ignition coil 220 is connected to the switch by two terminals 222 and 224 disposed one at each side of the battery terminal 2I6 so that'the main engine ignition circuit will be completed in either the booster engine manual or automatic position of the switch.

One end of the booster engine starter solenoid 208 is connected with the ground connection 226 the chamber with warm oil from the engine to improve the operation of the switch. 'If it is desired to combine the manifold pressure operated switch function with the oil pressure operated switch, the end of the member 236 opposite the contact member 232 may be connected to a diaphragm 248 in a pneumatic chamber 248 connected through a conduit 250 with the intake manifold 252 of the booster engine 42. Otherwise a separate manifold pressure switch may be provided, connected in series with the oil pressure controlled switch. I

When the booster engine is not operating, the compression spring 238 will move the member 238 into contact with themember' 232 thereby completing the ground connection of the solenoid 208. As soon, however, as the auxiliary engine starts, the partial vacuum in the manifold 252 acting on the diaphragm 246 moves the member 238 away from the member 232 thus interrupting the'solenoid circuit and preventing closing of the starting switch 204 while the booster engine manifold vacuum remains above a predetermined value. As soon as the booster engine builds up lubricating oil pressure this pressure applied to the end of the member 236 also acts to keep member 230 out of contact with the member 232 and prevents closing of the starter switch in the event the manifold vacuum of the booster engine should temporarily decrease while the engine is operating.

The end of the starter switch solenoid 208 opposite to the end connected to the switch 228 is connected through a conductor 254 with a terminal 256 of the switch 80.

If manual operation of the booster engine is desired, the lever 258 of the ignition switch 60 may be moved in the direction of the arrow labelled manual" which will connect the contact 2i4 with the contact 255 energizing the solenoid 208 to operate the starter 54 and this circuit will be broken by the switch 228 as soon as the booster engine is started. At the same time the booster engine ignition circuit including the coil 55 will be energized from the terminal 255 through the conductor 258 and a suitable ground connection indicated at 260.

If automatic operation of the booster engine is desired, the lever 258 will be moved in the direction of the arrow labelled automatic-which will connect the terminal 256 with the terminal operating.

- ama 262 which terminal is connected through a conductor 264 with one contact of a control unit 266. This unit is connected through a pair of pneumatic conduits 268 and 210 with the space ahead of and with the throat of a Venturi tube interposed between the main engine carburetor and the main engine intake manifold. all as particularly illustrated and described in said Letters Patent No. 2,384,781. From another terminal of control unit 266 a conductor 212 leads to the battery line 2l2 so that. when. the switch 60 connects the terminals 256 with the terminal 262, the starting circuit and ignition circuit of the auxiliary engine is connected to the battery 58 through the automatic control unit 266 which is so arranged that the booster engine will be started only when the speed and load factors of the main engine reach certain predetermined conditions. With the automatic circuit in operation the switch 228 will still act to disable the starter of the booster. engine and maintain the starter against operation as long as the boosterengine is operating, in the manner described above.

Preferably a switch 214 is included'in the conductor 264 and this switch may be operated by valve .53 which controls the ratio selection of the two speed rear axle in a manner such that the switch is closed only when the rear axle of the vehicle'is in its low speed ratio thus limiting automatic operation of the auxiliary engine to those occasions when the lower speed ratio of the two speed rear axle is being utilized.

This switch may be provided with a manually operated lockoutof some form known to the art so that, when desired; the main engine-maybe operated and the booster engine maintainedinoperative by operating the main engine on the Automatic controls and-maintaining the switch 214 open. If desired, a second switch 216 may be installed between the conductors H2 and 254 in order that the auxiliary engine may be manuauxiliary engine for testing the other purposes without the necessity of completing thev ignition circuit of the main engine.

2. In an automotive vehicle having a main engine and a booster engine, a main transmission and an auxiliary transmission; a clutch between said main engine and said main transmission; and a clutch between said booster engine and said auxiliary transmission; manually movable means for actuating said main engineclutch; open .of coaxial rotatable members connected respectively to said booster engine clutch and said meansfor actuating the main engine clutch; -a releasable coupling between said rotatable members operative to lock them for simultaneous movement or to permit relative movement therebetween; and fluid pressure responsive means connected to the intake manifold of the booster engine for operating said coupling to lock said rotatable members together to permit simultaneous actuation of said clutches only when said booster engine is operating.

3. In an automotive vehicle having a main engine, a booster'engine; a main variable speed transmission operatively associated with said main engine and an auxiliary variable speed transmission operatively associated with said booster engine; means operative only when said booster engineis operating and said main transmission is shifted to select certain drive speed ratios to shift said auxiliary transmission when said main transmission is shifted, said means comprising a valve in fluid communication with the intake manifold of said booster engine and mechanically connected with said main transmission so as to be operated when said main 7 transmission is shifted into said certain speed The] inventionmay be embodied in other speciflc forms without departing from the'spirit or essential characteristics thereof. The present I U embodiment is therefore to be considered in all respects, as illustrative and'not restrictivejthe scope of the invention being indicated by the appended iclaims rather than by theforegoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is: V

1. In anautomotive vehicle having a main engine and a booster engine, a main transmission and an auxiliary transmission, a clutch between said main engine and, said main transmission, and, a clutch between said booster, engine and said auxiliary transmission; manually movable means for operating said main engineclutch;

ratios; and a plurality of fluid pressure responsive power devices mechanically connected with said valve has a different operative position for each of the three-highest speeds of said main transmission, said auxiliary transmission has three gear trains providing three speeds corresponding to said three highest speeds of said main transmission, and said plurality of power devices comprises a first power device mechanically connected with one of the gear trains of said auxiliary transmission, a second power device mechanically connected with the other two of said gear trains and a third power device ope'ratively associated with said second power device and operativeto place said other two gear trains in neutral condition when said main transmission is in neutral.

5. Mechanism as defined in claim 3 wherein said valve comprises a casing having two parallel bores; a'respective plunger slidable in each bore 1 and having valve pistons and passages registershift lever to operate said valve.

6. In an automotive vehicle havinga main Q engine provided with a clutch and variable speed transmission and manual operating means therefor; and a booster engine also provided with a clutch and variable speed transmission; fluid pressure responsive means operatively connected between said main engine clutch and transmis sion and said booster engine clutch and transmission and energized by operation of said booster engine to render said manual means effective to operate said booster engine clutch simultaneously with operation of saidmain engine clutch and to shift said booster engine transmission simultaneously with shift of said main engine transmission to select certain drive speed ratios.

7. Mechanism as defined in claim 6 wherein said fluid pressure responsive means is energized by the pressure diiferences between atmospheric pressure and the intake manifold pressure of said booster engine.

8. In an automotive vehicle having a main engine and a variable speed transmission driven thereby and a booster engine and a variable speed transmission driven thereby, means for shifting said main transmission, and means operative only when said booster engine is operating and said main transmission is shifted to select certain drive speed ratios to shift said booster transmission when the main transmission is shifted, said means comprising a valve operatively connected with the shifting means for. said main engine transmission, pressure responsive devices meportions registerable with I said ports, means mechanically connecting said valve plungers with said main engine transmission, fluid pressure actuated devices mechanically connected with said booster engine transmission to shift the gears thereof and connected with respective valve ports by pressure, fluid lpressure transmitting connections; and means connected with said valve and providing. energizing fluid pressure when said booster engine is operating whereby shifting to select said certain drive speed gear ratios of said main engine transmission will shift said booster engine transmission to correspond- .-ing gear ratios when said booster engine is operating.

10. In an automotive vehicle having a main engine provided with a clutch, manual operating means for said clutch, and a booster engine also provided with a clutch; connecting means between said main engine clutch and said booster engine clutch for imparting movement of said manual operating means 'to said booster engine clutch, resilient means operative to render said connecting means inoperative, and means energized by said booster engine operative to overcome said resilient means'and render said connecting means eflective to operate said booster engine clutch.

11. In an automotive vehicle, a main engine connected to a variable speed transmission having drive speed ratio selecting means, a booster engine connected to a variable speed transmission having speed ratios corresponding to, certain of the speed ratios of said main engine transmission. fluid pressure servo means operably connected to said booster engine transmission and adapted to be selectivelyenergized from a fluid pressure source only when said booster engine is operating, said servo means serving to select the speed ratios in the booster transmission corresponding to said certain speed ratios in the main engine transmission, and means actuated by said speed ratio selecting means for the main engine transmission for controlling said energizetion of said servo means. I

12. In the vehicle defined in claim 11, said last means comprising a fluid pressure conduit system between said source and said servo means and a selector valve in said system adapted to be moved by said selecting means.

13. In the vehicle defined in claim 1, said means operatively associated with said'motion transmitting means and said booster engine comprising a fluid pressure responsive device connected with the intake manifold of said booster engine and ,a releasable coupling in said motion transmitting means actuated by said device.

WALTER F. ROCKWELL. BEVERLY W. KEESE.

nnr'nnnncns orrnn The following references are of record in the file of this patent:

' UNITED STATES PATENTS Certificate of Correction Patent No. 2,462,902. March 1, 1949.

WALTER F. ROCKWELL ET AL. It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 12, after heretofore insert proposed; column 3, line 8, before the words to positively insert and; column 8, line 67, before clutch insert engine; column 9, line 30, for bear read gear;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 5th day of July, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

